C

题目

Theatre Square in the capital city of Berland has a rectangular shape with the size n × m meters. On the occasion of the city’s anniversary, a decision was taken to pave the Square with square granite flagstones. Each flagstone is of the size a × a.

What is the least number of flagstones needed to pave the Square? It’s allowed to cover the surface larger than the Theatre Square, but the Square has to be covered. It’s not allowed to break the flagstones. The sides of flagstones should be parallel to the sides of the Square.

Input
The input contains three positive integer numbers in the first line: n,  m and a (1 ≤  n, m, a ≤ 109).

Output
Write the needed number of flagstones.

Example
Input
6 6 4
Output
4

题意

有n*m平方米的广场铺a*a的大理石，规则是要覆盖整个广场，允许铺石面积大于广场面积。

解析

1.本题要注意数据的范围，由于n,m,a,是＜10^9，面积可能会溢出int（32位）的范围，故数据均用long long来定义。
2.要完全覆盖，则广场长和宽的长度要小于铺砖的长度。

代码

#include <stdio.h>int main(){    long long  n, m, a;    long long i=1,j=1;    long long x=0,y=0;    scanf("%I64d %I64d %I64d", &n, &m, &a);    if(n%a==0)        i=n/a;    else        i=n/a+1;    if(m%a==0)        j=m/a;    else        j=m/a+1;    printf("%I64d\n",i*j);    return 0;}